The present invention generally relates to a device for deterring pest animals from the vicinity of a culvert and is specifically directed to an apparatus that is adapted for mounting to a culvert and that produces sound, scent and light for the purposes of repelling beavers and preventing them from causing the road disruption and other property damage that may result from their damming about a culvert.
The beaver, North America's largest rodent, is an aquatic mammal that lives on a vegetarian diet of, mainly, leaves, sticks and tree bark. With their paddle-shaped feet and short legs, beavers are adept swimmers, but relatively slow land travelers. Consequently, beavers tend to spend most of their time either in or near bodies of water, as accessibility to swimmable water serves to minimize their vulnerabilities to land predators that are not inclined to pursue them in the water. So, to provide them more convenient and safer access to new food sources, beavers will make great efforts to expand their existing water habitats so as to encompass adjacent trees and vegetation that they wish to consume. To accomplish this, beavers assemble sticks, mud and rocks to effectively form dam structures in the paths of flowing water. A beaver dam can effectively stop the water's flow and force it to rise. Of course, where low-lying wooded land surrounds a water body, a rise in water level results in submersion of additional land and trees.
A location at which beavers commonly will erect a dam is in the vicinity of a culvert structure. By damming around the downstream end of a culvert, the normal flow of water exiting the culvert is blocked, and the water level is raised to form a “beaver pond.” This kind of damming may be useful for the beaver, but it is quite disruptive to human life when it causes roads to flood or to develop cracks and potholes due to water saturation of the roadbed. To that point, a study conducted at Cornell University revealed that, on average, 152 man-hours of repair work and $2,500 are spent, annually, on each road culvert through which beaver dams routinely obstruct the flow of water. Clearly, beavers can present a significant financial burden to departments of transportation and other public agencies responsible for maintaining roads, and they can pose similar burdens to private landowners whose lands are flooded and whose trees are destroyed by water submersion or by beavers feeding on them.
To prevent these problems at road culverts, there are a few basic methods of beaver damage abatement that are commonly used. One such method is use of a water level control device. However, many of these devices are difficult to install. Due to a host of factors, typical water level control devices are installable at only a small percentage of all road culverts. These device also require continuous maintenance, so, they often are not the most viable solutions for preventing beaver damming—particularly, around culverts.
A second method of beaver damage abatement near culverts is use of an exclusion device that serves as a physical barrier to prevent beavers from coming within a certain distance of a culvert. For example, when a cylindrical fence is attached to and extends from the end of a culvert, beavers must form a dam much longer than they ordinarily would build in order to restrict the dispersed water flow and cause the water level to rise. However, because beavers often are capable of tunneling underneath exclusion devices to dam inside of them, such devices may be rendered ineffective.
A couple of other basic methods of preventing beaver damming are trapping and shooting. However, because of the potential enormity of the beaver population around water habitats, these methods may ultimately prove futile as well. Furthermore, in many instances, either firearms use prohibitions or animal rights considerations may dissuade one from resorting to these methods even where they potentially could be effective.
Finally, another solution for preventing beaver damming activity around a culvert, and a solution that the present invention embodies, is use of a deterrent device. For examples, U.S. Pat. No. 6,856,243 to Smith et al. and U.S. Pat. No. 5,892,446 to Reich disclose devices that detect the presence of animals and then use light and sound to ward them off. Nevertheless, it can be appreciated that there still exists a primary need for a pest animal deterrent apparatus that is specifically adapted for attachment to and use at road culverts and similar structures, principally, for preventing beaver damming thereabout. Secondarily, such an apparatus should: (1) be culvert mountable in a way that is non-intrusive and that allows for easy detachment from one culvert and redeployment to another; (2) allow for easy adjustment of its zone of detection; and (3) operate continuously off of its own power source, but with minimal power consumption and maintenance. The present invention substantially fulfills this existing need and possesses the foregoing attributes.